The long-term goal of this project is to characterize the processes involved in the regulation of cellular levels of cyclic nucliotides in microbial cells. Our major concentration has involved the enzyme adenylate cyclase, which appears to play the major regulatory role in controlling cyclic AMP levels. The focus of interest at the moment is to construct a library of new strains of E. coli which will allow us to understand better the regulation of adenylate cyclase activity by transport systems.